diff --git a/OpenSim/Region/ScriptEngine/YEngine/MMRScriptCodeGen.cs b/OpenSim/Region/ScriptEngine/YEngine/MMRScriptCodeGen.cs
index e29a51504c..35711c166f 100644
--- a/OpenSim/Region/ScriptEngine/YEngine/MMRScriptCodeGen.cs
+++ b/OpenSim/Region/ScriptEngine/YEngine/MMRScriptCodeGen.cs
@@ -66,7 +66,7 @@ namespace OpenSim.Region.ScriptEngine.Yengine
     {
         public static readonly string OBJECT_CODE_MAGIC = "YObjectCode";
         // reserve positive version values for original xmr
-        public static int COMPILED_VERSION_VALUE = -3;  // decremented when compiler or object file changes
+        public static int COMPILED_VERSION_VALUE = -4;  // decremented when compiler or object file changes
 
         public static readonly int CALL_FRAME_MEMUSE = 64;
         public static readonly int STRING_LEN_TO_MEMUSE = 2;
diff --git a/OpenSim/Region/ScriptEngine/YEngine/MMRScriptTokenize.cs b/OpenSim/Region/ScriptEngine/YEngine/MMRScriptTokenize.cs
index 0a79f1acfc..f1e3424d6a 100644
--- a/OpenSim/Region/ScriptEngine/YEngine/MMRScriptTokenize.cs
+++ b/OpenSim/Region/ScriptEngine/YEngine/MMRScriptTokenize.cs
@@ -1339,13 +1339,13 @@ namespace OpenSim.Region.ScriptEngine.Yengine
     {
         public TokenKwAndAndAnd(TokenErrorMessage emsg, string file, int line, int posn) : base(emsg, file, line, posn)
         {
-            binOpConst = TokenRValConstOps.Null;
+            binOpConst = TokenRValConstOps.binConstsLogicAndAnd;
             unOpConst = TokenRValConstOps.Null;
             sdtClassOp = false;
         }
         public TokenKwAndAndAnd(Token original) : base(original)
         {
-            binOpConst = TokenRValConstOps.Null;
+            binOpConst = TokenRValConstOps.binConstsLogicAndAnd;
             unOpConst = TokenRValConstOps.Null;
             sdtClassOp = false;
         }
@@ -1358,13 +1358,13 @@ namespace OpenSim.Region.ScriptEngine.Yengine
     {
         public TokenKwOrOrOr(TokenErrorMessage emsg, string file, int line, int posn) : base(emsg, file, line, posn)
         {
-            binOpConst = TokenRValConstOps.Null;
+            binOpConst = TokenRValConstOps.binConstsLoginOrOr;
             unOpConst = TokenRValConstOps.Null;
             sdtClassOp = false;
         }
         public TokenKwOrOrOr(Token original) : base(original)
         {
-            binOpConst = TokenRValConstOps.Null;
+            binOpConst = TokenRValConstOps.binConstsLoginOrOr;
             unOpConst = TokenRValConstOps.Null;
             sdtClassOp = false;
         }
@@ -1457,8 +1457,8 @@ namespace OpenSim.Region.ScriptEngine.Yengine
     }
     public class TokenKwAndAnd: TokenKw
     {
-        public TokenKwAndAnd(TokenErrorMessage emsg, string file, int line, int posn) : base(emsg, file, line, posn) { binOpConst = TokenRValConstOps.Null; unOpConst = TokenRValConstOps.Null; sdtClassOp = true; }
-        public TokenKwAndAnd(Token original) : base(original) { binOpConst = TokenRValConstOps.Null; unOpConst = TokenRValConstOps.Null; sdtClassOp = true; }
+        public TokenKwAndAnd(TokenErrorMessage emsg, string file, int line, int posn) : base(emsg, file, line, posn) { binOpConst = TokenRValConstOps.binConstsLogicAndAnd; unOpConst = TokenRValConstOps.Null; sdtClassOp = true; }
+        public TokenKwAndAnd(Token original) : base(original) { binOpConst = TokenRValConstOps.binConstsLogicAndAnd; unOpConst = TokenRValConstOps.Null; sdtClassOp = true; }
         public override string ToString()
         {
             return "&&";
@@ -1466,8 +1466,8 @@ namespace OpenSim.Region.ScriptEngine.Yengine
     }
     public class TokenKwOrOr: TokenKw
     {
-        public TokenKwOrOr(TokenErrorMessage emsg, string file, int line, int posn) : base(emsg, file, line, posn) { binOpConst = TokenRValConstOps.Null; unOpConst = TokenRValConstOps.Null; sdtClassOp = true; }
-        public TokenKwOrOr(Token original) : base(original) { binOpConst = TokenRValConstOps.Null; unOpConst = TokenRValConstOps.Null; sdtClassOp = true; }
+        public TokenKwOrOr(TokenErrorMessage emsg, string file, int line, int posn) : base(emsg, file, line, posn) { binOpConst = TokenRValConstOps.binConstsLoginOrOr; unOpConst = TokenRValConstOps.Null; sdtClassOp = true; }
+        public TokenKwOrOr(Token original) : base(original) { binOpConst = TokenRValConstOps.binConstsLoginOrOr; unOpConst = TokenRValConstOps.Null; sdtClassOp = true; }
         public override string ToString()
         {
             return "||";
@@ -1574,8 +1574,8 @@ namespace OpenSim.Region.ScriptEngine.Yengine
     }
     public class TokenKwExclam: TokenKw
     {
-        public TokenKwExclam(TokenErrorMessage emsg, string file, int line, int posn) : base(emsg, file, line, posn) { binOpConst = TokenRValConstOps.Null; unOpConst = TokenRValConstOps.Null; sdtClassOp = true; }
-        public TokenKwExclam(Token original) : base(original) { binOpConst = TokenRValConstOps.Null; unOpConst = TokenRValConstOps.Null; sdtClassOp = true; }
+        public TokenKwExclam(TokenErrorMessage emsg, string file, int line, int posn) : base(emsg, file, line, posn) { binOpConst = TokenRValConstOps.Null; unOpConst = TokenRValConstOps.unOpExclam; sdtClassOp = true; }
+        public TokenKwExclam(Token original) : base(original) { binOpConst = TokenRValConstOps.Null; unOpConst = TokenRValConstOps.unOpExclam; sdtClassOp = true; }
         public override string ToString()
         {
             return "!";
@@ -2201,8 +2201,10 @@ namespace OpenSim.Region.ScriptEngine.Yengine
             double r;
             try
             {
-                if ((left is int) && (right is int))
+                if ((left is int li) && (right is int ri))
                 {
+                    if(li == -2147483648 && ri == -1)
+                        return -2147483648;
                     return (int)left / (int)right;
                 }
                 if ((left is double) && (right is int))
@@ -2238,9 +2240,11 @@ namespace OpenSim.Region.ScriptEngine.Yengine
             double r;
             try
             {
-                if ((left is int) && (right is int))
+                if ((left is int li) && (right is int ri))
                 {
-                    return (int)left % (int)right;
+                    if (li == -2147483648 && ri == -1)
+                        return 0;
+                    return li % ri;
                 }
                 if ((left is double) && (right is int))
                 {
@@ -2297,98 +2301,30 @@ namespace OpenSim.Region.ScriptEngine.Yengine
             {
                 return (int)left & (int)right;
             }
-            if((left is int) && (right is double))
-            {
-                return (int)left & (int)(double)right;
-            }
-            if((left is double) && (right is int))
-            {
-                return (int)(double)left & (int)right;
-            }
-            if((left is double) && (right is double))
-            {
-                return (int)(double)left & (int)(double)right;
-            }
             return null;
         }
         public static object LSh(object left, object right)
         {
             if((left is int) && (right is int))
-            {
                 return (int)left << (int)right;
-            }
-            if((left is int) && (right is double))
-            {
-                return (int)left << (int)(double)right;
-            }
-            if((left is double) && (right is int))
-            {
-                return (int)(double)left << (int)right;
-            }
-            if((left is double) && (right is double))
-            {
-                return (int)(double)left << (int)(double)right;
-            }
             return null;
         }
         public static object Or(object left, object right)
         {
             if((left is int) && (right is int))
-            {
                 return (int)left | (int)right;
-            }
-            if((left is int) && (right is double))
-            {
-                return (int)left | (int)(double)right;
-            }
-            if((left is double) && (right is int))
-            {
-                return (int)(double)left | (int)right;
-            }
-            if((left is double) && (right is double))
-            {
-                return (int)(double)left | (int)(double)right;
-            }
             return null;
         }
         public static object RSh(object left, object right)
         {
             if((left is int) && (right is int))
-            {
                 return (int)left >> (int)right;
-            }
-            if((left is int) && (right is double))
-            {
-                return (int)left >> (int)(double)right;
-            }
-            if((left is double) && (right is int))
-            {
-                return (int)(double)left >> (int)right;
-            }
-            if((left is double) && (right is double))
-            {
-                return (int)(double)left >> (int)(double)right;
-            }
             return null;
         }
         public static object Xor(object left, object right)
         {
             if((left is int) && (right is int))
-            {
                 return (int)left ^ (int)right;
-            }
-            if((left is int) && (right is double))
-            {
-                return (int)left ^ (int)(double)right;
-            }
-            if((left is double) && (right is int))
-            {
-                return (int)(double)left ^ (int)right;
-            }
-            if((left is double) && (right is double))
-            {
-                return (int)(double)left ^ (int)(double)right;
-            }
             return null;
         }
         public static object Add(object left, object right)
@@ -2570,12 +2506,49 @@ namespace OpenSim.Region.ScriptEngine.Yengine
                 return null;
             return (res != 0) ? 1 : 0;
         }
+
+        public static object binConstsLogicAndAnd(object left, object right)
+        {
+            if ((left is int li) && (right is int ri))
+            {
+                if (li == 0)
+                    return 0;
+                if (ri == 0)
+                    return 0;
+                return 1;
+            }
+            return null;
+        }
+
+        public static object binConstsLoginOrOr(object left, object right)
+        {
+            if ((left is int li) && (right is int ri))
+            {
+                if (li != 0)
+                    return 1;
+                if (ri != 0)
+                    return 1;
+                return 0;
+            }
+            return null;
+        }
+
+        public static object unOpExclam(object left)
+        {
+            if ((left is int li))
+            {
+                if (li == 0)
+                    return 1;
+                return 0;
+            }
+            return null;
+        }
     }
 
-    /*
-     * Various datatypes.
-     */
-    public abstract class TokenType: Token
+/*
+ * Various datatypes.
+ */
+public abstract class TokenType: Token
     {
 
         public TokenType(TokenErrorMessage emsg, string file, int line, int posn) : base(emsg, file, line, posn) { }
diff --git a/OpenSim/Region/ScriptEngine/YEngine/XMRInstCtor.cs b/OpenSim/Region/ScriptEngine/YEngine/XMRInstCtor.cs
index 7e13ae4962..3acaef8a9b 100644
--- a/OpenSim/Region/ScriptEngine/YEngine/XMRInstCtor.cs
+++ b/OpenSim/Region/ScriptEngine/YEngine/XMRInstCtor.cs
@@ -86,6 +86,7 @@ namespace OpenSim.Region.ScriptEngine.Yengine
             m_StackSize = stackSize;
             m_StackLeft = stackSize;
             m_HeapSize = heapSize;
+            m_heapUsed = 0;
             m_CompilerErrors = errors;
             m_StateFileName = GetStateFileName(scriptBasePath, m_ItemID);